6 Gb SAS磁盘架和缆线导致SSD延迟高于预期
适用场景
- ONTAP 9
- AFF
- SAS 6 Gb HBA
问题描述
qos statistics命令显示磁盘延迟：
cluster1::> qos statistics volume latency show -vserver svm1 -volume vol1 Workload ID Latency Network Cluster Data Disk QoS Max QoS Min NVRAM --------------- ------ ---------- ---------- ---------- ---------- ---------- ---------- ---------- ---------- -total- - 4.71ms 185.00us 7.00us 468.00us 4.04ms 0ms 0ms 11.00us vol1-wid32140 32140 22.22ms 86.00us 125.00us 904.00us 21.11ms 0ms 0ms 1.00us -total- - 4.58ms 253.00us 7.00us 991.00us 3.32ms 0ms 0ms 11.00us vol1-wid32140 32140 29.69ms 90.00us 162.00us 2.61ms 26.82ms 0ms 0ms 1.00us -total- - 2.55ms 229.00us 8.00us 589.00us 1.71ms 0ms 0ms 13.00us vol1-wid32140 32140 18.84ms 61.00us 314.00us 136.00us 18.32ms 0ms 0ms 1.00us -total- - 4.33ms 198.00us 9.00us 1221.00us 2.88ms 0ms 0ms 13.00us vol1-wid32140 32140 177.16ms 113.00us 226.00us 108.03ms 68.79ms 0ms 0ms 2.00us
Cluster::> set -privilege diag Warning: These diagnostic commands are for use by NetApp personnel only. Do you want to continue? {y|n}: y Cluster::*> statistics start -object disk -counter "io_queued|io_pending" Statistics collection is being started for sample-id: sample_148 Cluster::*> statistics show -filter "io_queued>10|io_pending>10" Object: disk Instance: 0d.23.13 Start-time: 12/5/2022 16:48:26 End-time: 12/5/2022 16:51:58 Elapsed-time: 212s Scope: node1 Number of Constituents: 1 (complete_aggregation) Counter Value -------------------------------- -------------------------------- io_queued 19 io_pending 8 ... Cluster::*> node run -node node1 -command statit -b Cluster::*> node run -node node1 -command statit -e Disk Statistics (per second) ut% is the percent of time the disk was busy. xfers is the number of data-transfer commands issued per second. xfers = ureads + writes + cpreads + greads + gwrites chain is the average number of 4K blocks per command. usecs is the average disk round-trip time per 4K block. disk ut% xfers ureads--chain-usecs writes--chain-usecs cpreads-chain-usecs greads--chain-usecs gwrites--chain-usecs /data_aggr1/plex0/rg0: 0c.01.2 80 2510.99 1525.62 5.95 763 389.58 11.11 2682 595.79 5.22 1318 0.00 .... . 0.00 .... . 0c.01.3 81 2502.32 1510.75 5.96 758 393.43 11.27 2706 598.14 5.15 1348 0.00 .... . 0.00 .... . 0c.01.4 81 2518.91 1528.01 5.93 762 392.18 11.45 2661 598.72 5.12 1364 0.00 .... . 0.00 .... . ...